Concrete cube testing in Milton Keynes.

Yes. This is the one area where that is a plain yes. Fresh concrete testing is offered within about an hour’s drive of the laboratory, and Milton Keynes, Bletchley, Newport Pagnell, Bedford, Northampton, Buckingham, Aylesbury and Luton all sit inside that. We attend the pour, test the slump or flow on arrival and make the cubes at the point of placement.

Yes. Cubes made by your own team or your supplier can be dropped at the door during working hours. Ring before you set off so someone is ready to book them in, and mark each cube with a unique reference. Bring them damp, after at least 16 hours and within 3 days of casting, and they go straight into the curing tank.

Because the commonest cause of a disputed cube result is poor early curing, and distance makes that worse. A cube that spends its first days in a cold cabin or the back of a van is not the cube the standard describes. Here, cubes are in a controlled tank at 20 ± 2 °C within hours of demoulding, so the result reflects the concrete and not the journey.

The ages your specification sets. Most structural concrete is tested at 7 and 28 days, with conformity normally judged at 28 days. Because there is no courier leg, early-age tests at 1, 2 or 3 days are practical here where striking or loading depends on them. Tell us the ages when you book.

The cube is loaded to failure in a calibrated compression machine, and the strength is the maximum load divided by the cross-sectional area, reported in newtons per square millimetre. Testing is usually specified to BS EN 12390-3. The report gives the reference, age at test, dimensions, failure load, strength and the failure pattern.

Yes. On a pour visit we measure consistence on arrival, by slump or by flow for more fluid mixes, and record it against the delivery ticket before the concrete is placed. A load that is outside the specified consistence can then be dealt with at the truck, which is a great deal cheaper than dealing with it after 28 days.

Your specification sets the sampling rate, usually by reference to BS 8500 and BS EN 206, and on a large floor it is normally tied to the volume placed. A set from each sample covering 7 and 28 days, plus a spare, is common. Some floor specifications also ask for flexural strength beams, which is a different test, so check what the designer wants.

Check the cube first. Identification, age, curing history, dimensions and failure pattern can all explain a low figure. Where we made and cured the cubes ourselves, most of those doubts are already closed. If the result stands, your engineer decides what follows, commonly a spare cube at a later age or cores from the element, which locally we can often cut within a day or two.

It affects the concrete that should be specified. Oxford Clay contains pyrite and sulfates, so foundations and other buried concrete are designed to a sulfate class from the ground investigation. A cube test confirms strength, not sulfate resistance, so the delivery ticket should be checked against the specified mix. We test soil samples for sulfate in the same laboratory.

100 mm cubes suit most structural concrete with 20 mm aggregate. 150 mm cubes are needed where the aggregate is larger, because BS EN 12390-1 relates specimen size to maximum aggregate size. If we are making the cubes, tell us the mix and we bring the right moulds.

Hixtra holds UKAS accreditation to ISO/IEC 17025 under schedule number 8996. Accreditation is granted method by method, not to the company as a whole. Most of our soil and aggregate tests are on the schedule, and some concrete tests are still going through the accreditation process. This matters most here, because this is where our fresh concrete work happens. If your specification requires accredited results, name the tests when you enquire and we will confirm which are on the current schedule before you book.

No. A cube is compacted and cured under standard conditions and shows what the concrete as supplied can achieve. Concrete in the structure is placed and cured in place and is normally somewhat weaker. Cube results judge the conformity of the supply. In-place strength is assessed from cores.

At the Hixtra laboratory in Milton Keynes, which is also our head office. 01908 505833 rings there. Every cube we test from anywhere in England and Wales is cured and crushed in the same place, on the same calibrated machine. Local clients simply have the shortest journey to it.